Stargazing in Oman

Equipment Used:
My airline transportable travel scope is the APM TMB 105/650 LW with 2″ Feathertouch focuser. Weight including tube rings is 4.7kg. Minimum length for transportation is 450mm (17.4”) though this requires the focuser be removed, which is a simple matter of loosening 3 small Allen bolts.

The mount I used was the Teleoptic Giro Ercole. The weight of the mount head is approximately 3kg and is capable of supporting 8kg on one arm without the use of a counterweight. With a counterweight, the load capacity increases to 18kg on each arm which can be two scopes so has use outside of a travel mount. For anyone considering a high quality Alt Az mount, I cannot recommend the Ercole enough. For travelling in particular, the lack of required counterweights up to 8kg loads is invaluable when pressing against airline baggage limits. However, while the mount is smooth with my APM 105, the performance with a counterweight is nothing short of a revelation. As such, for domestic travel where I can afford the extra weight, I now use a counterweight.

The tripod used (with the requirement that it fit in my checked suitcase – most dedicated astronomical tripods are just too long) is the Gitzo Series 5 5532S 6X Carbon Fibre tripod. Weight is 2.8kg and minimum length for transportation is 620mm. The tripod is rated to carry 40kg so while not a dedicated astronomical tripod; it is more than up to the job. The dampening time even after a good hit is no more than a second or so.

With this setup, I took 3 eyepieces, a 3-6mm Nagler Zoom, a 10mm Televue Delos and the 35mm Televue Panoptic. This gives me a magnification and true field range of 19x – 216x and 3.4 degree – 0.2 degree respectively. All sitting in a 2” William Optics dielectric diagonal. I also took a 2” UHC filter with me.

The scope OTA, the EPs, diagonal and focuser were transported carry-on, in a Pelican 1510 case (see picture below). The tripod, the mount and the tube rings were packed in my checked suitcase. The only issue I had was how to transport the finder. Fortunately I flew with British Airways who permit two pieces of carry-on luggage (the 2nd smaller than the first) so I included that in a back pack along with other items I wanted to carry with me in the cabin. For future trips abroad, I am switching to a smaller zero power red dot finder.

APM 105 In Pelican 1510 Case

APM 105 In Pelican 1510 Case

Experience Transporting the Equipment:
I thought it might be useful to share my experiences of taking this equipment abroad as I have seen many questions on astronomy forums regarding issues with clearing airport security etc.

At Heathrow I had no issues what so ever. I fully expected to be asked to open my Pelican case as I can only imagine what all the equipment must look like on the x-ray scanners, and while I did note that security paused to look closer, they obviously saw nothing in particular to alarm them. Quite ironically though, they did see something they did not like in my backpack and I had to empty the contents while they took a swab of the bag (they seemed to be doing this to almost every bag and clearing security took almost 30 minutes despite there being no more than 10 people in front of us – not sure if they were practicing or there was a credible threat on departure day). I also had my S&T Pocket Sky Atlas and a Planisphere in my backpack so was quickly able to explain what the finder was.

At Muscat International, all bags including carry-on luggage are scanned before you leave the luggage collection lounge. I thought this could be the first test and I was right. They asked me to open both the Pelican case and my main suitcase. There was a bit of language barrier but it was clear that the Teleoptic mount had concerned them, probably because they had not seen anything quite like it before. Very quickly they realised that I was carrying a telescope, but they initially seemed concerned that it was business related. After explaining to a better English speaker that it was a hobby we were on our way.

On the way back I encountered a similar problem at Muscat International, but only just before getting on the plane. Much like Russian Airports, all bags are scanned as you enter the terminal building. At security when entering the departure lounge, the Pelican case was scanned again. And then finally, at the departure gate, the bags are scanned for a third time! This particular time, I was asked to open my bags. The English of all concerned was very poor, but fortunately a quick point at the star atlas and showing them the telescope and we were on the plane.

So not completely without issue, but also fairly straight forward and made easier by having a star atlas to hand to help explain what I was carrying.

Observing:
The holiday was not primarily an observing holiday which meant we would be in Oman during the full moon, so each observing session without the bright moon was shorter than the last.

Muscat:
We stayed at the Chedi in Muscat, which benefits from a private beach some 375m in length with a North facing aspect looking into the Arabian Sea. This I thought would provide an ideal observing location while we stayed there for the first few days of our holiday. However, I had not realised just how hazy and humid (between May and September according to locals) Muscat actually was. Combined with Muscat being a modern, sprawling 21st century metropolis (very long and thin city that hugs the coast line), with flashes of its history dotted around the city, and what appears to be no regulations governing light use, led to light pollution far worse than what we have to suffer in central London. The thick orange soup (combination of older low pressure sodium and mercury as well as the new high pressure white lights) extended to at least an altitude of 35 degrees above the horizon (even North into the Arabian Sea), and was so bad that I was unable to visually locate Jupiter an hour after it had risen. So unfortunately for the first couple of days of the holiday no stargazing was really possible.

The Mountains:
Oman has a very interesting and varied geology, including a mountain range with peaks a little above 3000m. We stayed at “The View” in the Jabal Shams Mountains, located over 1000m above the small town of Hamra below. As will often be seen in mountain ranges all over the world, clouds will form above them, and we experienced this both days that we stayed here. On the second day we were treated to a very impressive thunder storm that battered the town below. Fortunately the clouds cleared away after dark. Stargazing was conducted both before and after the moon set (by now a waxing gibbous approximately 70% illuminated). I would estimate that post moon set, the sky was Magnitude 5.5+, with only a small amount of light pollution from the town below impacting the view of the night sky, with the Milky Way being fairly obvious, especially near the zenith. However, due to lights placed around the camp so guests could navigate in the dark, it was never possible to fully dark adapt my eyes as I was not able to fully escape their glare (the camp is gated and fenced and closes late evening). As such, the stargazing was pleasing but not stellar.

One interesting observation that I did make was the tranquillity of the atmosphere over the mountains. And that was not good. While 2 days does not provide enough evidence for the stability of the seeing all year round, during my stay high power planetary work was not an option. At this location, Jupiter was passing within a couple of degrees of the zenith, and yet, just using the Delos 10mm, yielding only 65x magnification, atmospheric turbulence was very apparent on disc of Jupiter.

Jabal Shams Mountains

Jabal Shams Mountains

The Desert:
While in the desert, we stayed at the “Desert Night Camp” which is 11km into the desert from a small village (with no external lights that I noticed) called Ibra. This location was very isolated, and if anywhere on this holiday would provide me with those magical dark skies, this would be it. The camp did not disappoint. I did a small amount of observing before the moon set (now over 80% illuminated and setting around 3am), but wanted to make sure I would be able to go through to sunrise, so slept for a few hours before hand.

Amusingly, I did experience something that is the bane of all us who observe from our more northern climes in Europe, and that was a dew problem…In the desert! At 2:30am when I took my scope outside from my air conditioned tent (this is not like any normal tent – My GF does not do camping, but she will do “glamping,” and this definitely qualified) the optics of the scope immediately fogged up, and moisture was easy to detect upon touching the tube. Despite being in the desert, there was a small amount of moisture in the air, and my scope, stored in the rather cool tent, had cooled below the dew point. Normally this would be a bit of a catastrophe, but fortunately the temperature was still in the mid to high 20s, so within 15 to 20 minutes all the fogging had cleared and the scope had come close to thermal equilibrium. During that time, my eyes had become dark adapted. And they were being treated to quite some sky (and a bright Iridium Flare in Cassiopeia).

The milky was about as prominent as I have ever seen it, running from the North West in Lyra / Cygnus to Monoceros and Canis Major in the South East. That was not the only ethereal light I got to enjoy that night though. The zodiacal light was also very obvious in the sky. This was only the third time I have seen this phenomena, the first during an observing trip as part of my Physics and Astrophysics degree at the “Observatorio del Teide” on Mt Teide in Tenerife and the second being at the Sossusvlei Desert Camp in Namibia in 2011 (where I was lucky enough to observe for 4 nights under magnitude 6+ skies with a 12” scope). Turning my attention to the Pleiades (at an altitude of over 80 degrees), unaided I was able to see 13/14 stars. I knew this was going to be a good couple of hours, observing under some of the darkest skies I have ever seen.

I started with the Double Cluster in Perseus, not remotely challenging to find, as I could see it unaided as a fairly birght hazy patch of light. Without any exaggeration, when I peered through the 10mm Delos and its 1.1 degree field of view, I was greeted with an explosion of stars, almost overwhelming in number. I have viewed this object more times than I can count over the last 20 years, and I have never seen anything quite like it. The view was comparable to my 11 inch SCT from light polluted skies in Hampshire (where that scope lives), except this time I was easily able to fit both clusters in the field at the same time, something that cannot be achieved with the 11” and its maximum 0.94 degree field (using a 41mm Televue Panoptic which has the largest field stop diameter possible in a 2” EP). This left me anxious to view more open clusters, and one more than any other was beaconing to be viewed. M45.

With my 35mm Panoptic, the 4” Apo yields a field in excess of 3 degrees, easily framing the Pleiades, with sky to spare all around. What did I see when I looked? In one word, “nebulosity!” Not the first time I have seen this visually, but never quite so easy to spot as before. It was almost hard not to see it.

From there I decided to take a small jump to M42 in Orion. Always a showpiece object, but under these ideal conditions, it was simply stunning. Nebulosity extended to fill most of the field in the 10mm Delos, showing moulting and twisting within the nebula. I have already made the comparison to my 11 inch SCT, but the view was remarkably similar once again, and really demonstrated just what a huge difference a truly dark sky makes.

With the wind in my sails, and confidence running perhaps a little bit too high, I decided to attempt the impossible and swing up to Alnitak in Orion’s belt for an attempt at the Horse Head. I have only seen once before, using my 11” SCT from a decent dark sky site in the UK using a Hydrogen Beta filter (something I had not taken with me to Oman). I gave it no more than a 1% chance, but on the off chance, why not spend a minute or two trying? Alas, even though the Apo was providing miraculous, this was one miracle too far. I did however spot the flame Nebula (NGC 2024), near the limit of perceptibility, but it may well have been my imagination filling in what I know should be there. The more I think about this observing experience, the more confident I am that the Flame nebula was visible. It is notorious for being dependent on sky conditions, and the close proximity of Alnitak does not help, but some believe it to be the litmus test for whether an attempt at the Horsehead is even worth considering.

After such a successful set of views, I decided to put the Pocket Sky Atlas away, switch to the Panoptic, and start sweeping up all the open clusters in the Monoceros / Canis Major region that inhabit that part of the Milky Way. It did not disappoint and I lost track of just how many I found, but most of the time, the field was just full of stars.

Slightly hesitant, due to the disappointment in the Mountains, I decided to have another go at Jupiter around 4:30am, when it was around 3 degrees from the zenith. I started cautiously at only 65x, and was presented with a small, stable and fairly detailed disc, so I switched to the 3-6mm Nagler Zoom. Nothing could have prepared me for what was to come. Starting at 6mm, for a magnification of 108x, I was incredibly impressed with what I saw and I quickly realised that the seeing conditions were exceptionally good. I rapidly progressed through the click stops, from 5mm to 4mm and then to 3mm (216x). Jupiter is planet that is notorious for not taking magnification as well as Saturn for example, but here it was just getting better and better with each drop in EP focal length. I have never seen anything like it on Jupiter in 20 years of using telescopes. I felt like I was looking at a Damian Peach photo. The image never seemed to break down due to atmospheric turbulence, and the level of detail in the cloud bands was simply stunning. We all know the rule of thumb about 50x per inch of aperture, but the TMB lens in my Apo is one of the best I have ever used and really made me wish I had packed my 2x Powermate to see how far I could push it.

By now, the sky was beginning to brighten in the East (just after 5am – Yes I “lost” almost 30 minutes of precious dark skies to Jupiter, it was just that good), so I moved on to Venus which was about 25 degrees above the horizon. A nice disc illuminated about 70% was seen, but Venus, to be honest, has never excited me that much so I quickly moved on. With a now rapidly brightening sky encroaching on my dark sky, I swept around the sky picking out a few more objects of interest including NGC 2371/2 and NGC 2392 – The Eskimo Nebula, before finishing back at M42 (my first telescope Messier) and I watched it disappear into a blue sky. Though unable to watch the sun rise itself, due to sand dunes blocking about 6 degrees of sky, I stayed outside until I knew the sun was up, already anticipating the second night, of what would be an even shorter dark sky session. Unfortunately Mother Nature had other ideas…

At about 4pm the next day, the camp was hit by a very impressive (if you did not want to stargaze) sand storm, that last for around 2 hours. Visibility dropped to less than 20 feet. Staff at the camp told us rain was likely to follow, and it did, rather heavily, but unfortunately not at our site which would have helped to wash out the dust from the air. It was clear from looking at the moon that a lot of light was scattering, and the beam of my torch was clearly visible thanks to all the sand suspended in the air after we had finished dinner around 10pm. I decided I did not want to risk my scopes optics so shelved plans for a second night of stargazing in the desert.

For anyone considering a trip to Oman, I would highlight that the Camp has a telescope available on site. It was on display in the reception building so I took a quick look, but did not use it. It is a short tube 100mm diameter Newtonian on a light weight GEM. The focal length was stated as 1000mm, which means it was one of those scopes which has a built in correcting relay lens (i.e. a Barlow) in the focus drawtube, and most likely a F4 spherical primary mirror (with the hope that the Barlow would help mask the spherical aberration of the primary). The scope appeared to use 0.965” EPs, a 12mm Kellner type EP was in the scope. I do not know whether any other EPs are available, but with the caveat of a very quick assessment, the scope did not strike me as being of particularly high quality, though under these skies, I expect it would still provide a decent experience.

APM 105 at Sunrise

APM 105 at Sunrise

Ras Al Jinz:
The next two nights we stayed at the Ras Al Jinz Scientific and Visitor Centre on the coast. The site is a protected turtle reserve where thousands of turtles each year come to the beach to nest before returning to the sea. This deliberately coincided with the full moon to give us the best chance of seeing adult turtles nesting and hatchlings making their way to the sea. What we saw was incredible but left no time for stargazing. A quick assessment of the site indicated it holds lots of promise though if telescopes are your thing. It is about 50km from any settlement of note and there are plenty of secluded spots away from the already limited lights at the Centre (so not to interfere with the hatchlings which are attracted to light). It was also far less humid than Muscat (where we returned after our stay here to finish our holiday).

Conclusion:
While I managed less stargazing than I would have hoped due to light pollution in Muscat and sand storms in the desert, what I did manage was well worth the effort of carrying my refractor and related equipment with me on holiday. Managing to pack the tripod and mount in my main suitcase and keep it (just) under the 23kg weight limit certainly helped it not feel like it was a chore to carry the extra equipment around the country with us, and I feel confident to recommend the country for stargazing, particularly if you can get to the desert.

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2 Comments

  1. Pingback: Review of the APM TMB 105 f/6.2 Triplet Apo Refractor | Alpha Lyrae

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